The present invention relates to a lock for safety belts in vehicles, especially passenger cars, comprising a lock housing and a lock tongue disposed on the safety belt that can be swingably clamped in the housing, which is connected with a part fixed to the vehicle via a swing shaft so that the housing can be swung back in the direction of load.
A stationary belt lock with swingably clamped lock tongue is known from German AS No. 1,277,687, while a belt lock with swingable section is described in British Pat. No. 1,005,044. Moreover, it is known from German OS No. 2,400,898 that the running of the belt when there is an adjustable seat can be optimized by disposing the lock housing on the seat. Because of the requirement for single-handed operation in fastening or unfastening the belt, the known lock housing is held in a specific position by a bolt arrangement.
To fix the lock housing in its position by frictional engagement is not advantageous. With weak frictional engagement, the lock housing can be swung out of its predetermined position by vehicle jolts or other loads so that it is no longer possible to manipulate it with one hand. With strong frictional engagement on the other hand, the housing can be damaged if the belt is loaded, by a lock tongue engaging it that deviates pronouncedly from the normal direction so that the clamping device automatically releases the tongue, or else the tongue can no longer be released. In either case, the passenger could be considerably endangered.
An object of the present invention is therefore to provide a self-lock of the aforementioned type in which a position-fixation of the belt lock is accomplished in such a way that there is acceptable swinging back of the lock, with elimination of damage to the lock housing in accidental loading of it.
This and other objects of the present invention are attained by providing a lock for a safety belt in a vehicle such as a passenger car comprising a lock housing and a lock tongue disposed on the safety belt, which lock tongue can be swingably clamped in the lock housing, the lock housing being connected by a swing shaft with a part fixed to the vehicle so that the lock housing can be swung in the direction of load, a positively engaging check element being provided for fixing the lock housing to the part fixed to the vehicle in a position of use for single-hand operation, the check element, beginning at a predetermined load, releasing the lock housing so that it can be swung in the direction of load.
An advantage of the present invention resides in that the lock housing can swing back into a position corresponding to the direction of load, from its previous "fixed" position, starting at a specific load, and thereby damage or destruction from bursting of the lock housing is prevented. The predetermined load is of such rated value that damage to the lock housing is prevented and hence the functioning of the belt lock is preserved.
In one form of the present invention the lock housing is swingable about an essentially horizontal swing shaft and the positively engaging check element is a deformable check element. According to one embodiment of the present invention this deformable check element is a shear pin whereas in a second embodiment the deformable check element is formed by an extension of a part of said lock housing which is received in a hole in the part fixed to the vehicle.
In another form of the present invention the lock housing is swingable about an essentially horizontal swing shaft and the positively engaging check element is a locking member such as a ball which is biased in a locking position by a spring member.
These and other objects, features and advantages of the present invention will become more apparent from the following description when taken in connection with the accompanying drawings, which show, for purposes of illustration only, several embodiments in accordance with the present invention.